Analogue to digital conversion headache

As an enthusiastic, but somewhat clueless amateur, I wonder if I could call
upon the great wisdom round these parts?

I am having trouble deciding on a digital camera and lens combination to
replace my fairly ancient but trusty analogue workhorse combination. I own a
Minolta 500si body to which I mated a Sigma 50mm/f2.8/AF/Macro EX lens,
which give me nice undistorted sharp pics! This is used on an RR Beard copy
stand with a couple of 625watt floods diffused and reflection-shielded with
resin
polarisers to remove the reflections from framed artwork behind glass. On
top of that, I use a 55mm Hoya circular polarising filter on the camera
lens. So you can see why I need a fast lens!

Obviously working with RAW images is the way to go, as I can imagine I would
need to do some extensive post-processing work with Photoshop. However, I am
not very savvy with lens matters, and am a bit limited with the old budget.
I am aware of the limitations a digital sensor's field of view (?) has,
compared with the 'full frame' characteristics of the 35mm analogue camera.
As I use a copy stand with pretty restricted vertical height limits, I think
I am going to run into problems with a 1.5 - 1.7 crop factor inherent in
non-full frame sensors of semi-pro cameras, no? I sometimes need to
photograph pretty large paintings, and if they exceed about 30"x24" then I
have to insist that the painting is removed from the frame for shooting
horizontally on a tripod. But that can cause me loss of work, as many
paintings just cannot be removed easily from their frames.

I also need a camera capable of resolving to quite high pixel counts, so
that I can print out at A3 size without additional interpolation. It must
also be very good at achieving commercial levels (not archival quality) of
colour and tonal reproduction. I often have to make post-processing
corrections without the benefit of the original work to refer to, so the
least guesswork involved with colours and tones, the better and more
productive I shall be. :-)

I have in mind the following possibilities:

Would I be able to use my existing lens on say the new Minolta Maxxum/Dynax
7D?

On a bang-per-buck basis, I am also kind of tempted towards the Sigma SD10
with the foveon X3 sensor on the basis of both colour definition; sharpness
and the apparently excellent SPP processing software with the Light-fill
feature. (I downloaded the software and tried it out on a sample image) I
know this camera makes many round these parts look for a sick-bag, but
bearing in mind it will have a pretty dedicated and restricted use in a
studio, I shall not need to invest too heavily in a multitude of lenses and
feel stuck with them. That said, it has one of the most restrictive (for my
purpose) crop factor of most cameras in this range. (@ 1.7 IIRC)

I had better stop there, or I'll end up answering my own questions, God
forbid! Sorry for the ramble but my head hurts with all the trying to get to
grips with this technology. :-(

Kind regards

Nigel

Siggy wrote:

Would I be able to use my existing lens on say the new Minolta Maxxum/Dynax
7D?

Yes. The following is hastilly done, but should give you a good feel:

(Maxxum 100 f/2.8 macro lens (not at macro closeness); In camera JPG /
Fine, two softboxed strobes @ f/8, ISO 100)

Post processing: Unsharp mask only.

small v.
http://www.aliasimages.com/images/KM7D/ColBill_SM.U.jpg

(100% crop from above, view it at 100%, 800 KB)
http://www.aliasimages.com/images/KM...ill_FD.U.C.jpg

Full detail (large file, 2.5 MB), view it at 100%
http://www.aliasimages.com/images/KM7D/ColBill_FD.U.jpg

Crop issues: I'm sure you can work out an accurate means of shooting
framed works at any distance with them hanging flat against a wall. Or
find means to extend the height of your copy stand.

A3 (297 x 420) should print well at about 180 dpi without interpolation.
You're welcome to print the above FD.U file as a test. (Bear in mind
that the banknote was not perfectly flat for the shot, nor the lens
critically centered and aligned).

The only issue with the SD10 is that it is in fact a 3.4 Mpix
resolution. Some people feel that the colors are off in some areas.

Cheers,
Alan

--
-- r.p.e.35mm user resource: http://www.aliasimages.com/rpe35mmur.htm
-- r.p.d.slr-systems: http://www.aliasimages.com/rpdslrsysur.htm
-- [SI] gallery & rulz: http://www.pbase.com/shootin
-- e-meil: there's no such thing as a FreeLunch.

Alan Browne wrote:
snipped much pearls of wisdom

The only issue with the SD10 is that it is in fact a 3.4 Mpix
resolution. Some people feel that the colors are off in some areas.


Wow! What a quick and detailed response. I am humbled indeed. :-)
That is a lot to chew over and digest, but just wanted to say a quick word
of thanks for your kind interest, and will post back any further opinions on
that asap.

Kind regards

Nigel

Siggy wrote:
As an enthusiastic, but somewhat clueless amateur, I wonder if I could call
upon the great wisdom round these parts?

Obviously working with RAW images is the way to go, as I can imagine
I would need to do some extensive post-processing work with
Photoshop. However, I am not very savvy with lens matters, and am a
bit limited with the old budget. I am aware of the limitations a
digital sensor's field of view (?) has, compared with the 'full
frame' characteristics of the 35mm analogue camera. As I use a copy
stand with pretty restricted vertical height limits, I think I am
going to run into problems with a 1.5 - 1.7 crop factor inherent in
non-full frame sensors of semi-pro cameras, no?

Yes. You're only foing to get a 29 degree FOV with that 50mm lens.

I sometimes need to photograph pretty large paintings, and if they
exceed about 30"x24" then I have to insist that the painting is
removed from the frame for shooting horizontally on a tripod. But
that can cause me loss of work, as many paintings just cannot be
removed easily from their frames.

I also need a camera capable of resolving to quite high pixel
counts, so that I can print out at A3 size without additional
interpolation.

OK, that's a minimum of about 200 DPI. 3300 x 2338 pixels. About 8
megapixels.

It must also be very good at achieving commercial levels (not
archival quality) of colour and tonal reproduction. I often have to
make post-processing corrections without the benefit of the original
work to refer to, so the least guesswork involved with colours and
tones, the better and more productive I shall be. :-)

I have in mind the following possibilities:

Would I be able to use my existing lens on say the new Minolta
Maxxum/Dynax 7D?

On a bang-per-buck basis, I am also kind of tempted towards the Sigma SD10
with the foveon X3 sensor on the basis of both colour definition; sharpness

a. It doesn't have the resolution you need at 3 Mpix.
b. It doesn't have the colour rendition you need.

and the apparently excellent SPP processing software with the
Light-fill feature.

Which you certainly aren't going to need on a copy camera.

Andrew.

Siggy wrote:

Alan Browne wrote:
snipped much pearls of wisdom

The only issue with the SD10 is that it is in fact a 3.4 Mpix
resolution. Some people feel that the colors are off in some areas.



Wow! What a quick and detailed response. I am humbled indeed. :-)
That is a lot to chew over and digest, but just wanted to say a quick word
of thanks for your kind interest, and will post back any further opinions on
that asap.

I would have hoped that your interest was in fact in the rest of the
post, not the Sigma bit.


--
-- r.p.e.35mm user resource: http://www.aliasimages.com/rpe35mmur.htm
-- r.p.d.slr-systems: http://www.aliasimages.com/rpdslrsysur.htm
-- [SI] gallery & rulz: http://www.pbase.com/shootin
-- e-meil: there's no such thing as a FreeLunch.

Alan Browne wrote:
Siggy wrote:

Alan Browne wrote:
snipped much pearls of wisdom


I would have hoped that your interest was in fact in the rest of the
post, not the Sigma bit.

I was indeed. I had hoped my snippage comment further up would have
indicated as much. ;-)

Now to your info.

Firstly then, the Sigma is a non-starter. Ta!

Secondly, you stated "(........... two softboxed strobes @ f/8, ISO 100)"

Now that's interesting because I have the matter of suitable lighting for
digital cameras in my mind, but thought it would be too OT for this group.
However, since you offered advice, can I just clarify that you mean 'strobe'
to be a flash-type light as opposed to the always-on flood-type which I
currently use? If so, why should I change my current lighting setup? (I am
thinking cost consequences here)
Further, I seem to recall a white paper written by Betterlight on this
subject, and their eventual recommendations were to use fluorescent lighting
with a couple of filters (daylight AND tungsten, IIRC) to counter the
metamerism effect on certain colours when using digital sensors. Any
comments?

lid wrote:


Yes. You're only foing to get a 29 degree FOV with that 50mm lens.

Hmm. I don't suppose you could also let me have the FOV (in degrees) of the
lens in my existing setup, could you? :-)


OK, that's a minimum of about 200 DPI. 3300 x 2338 pixels. About 8
megapixels.

Ok. Minolta D7 seems a bit weak in that respect then. Are we looking at the
Canon 350D here, I wonder?

(on Sigma SD10)
a. It doesn't have the resolution you need at 3 Mpix.
b. It doesn't have the colour rendition you need.

Yup, gotcha. Thanks.

and the apparently excellent SPP processing software with the
Light-fill feature.

Which you certainly aren't going to need on a copy camera.

I mentioned that as I have always found (in an image containing significant
dark or shadow areas) it difficult to get the scanner to extract as much
detail from the dark areas of the photographic print without blowing out the
delicate highlights. However, I forgot that I shall be bypassing that stage
with a digital camera, so I stand corrected. Thanks.

Siggy wrote:

Secondly, you stated "(........... two softboxed strobes @ f/8, ISO 100)"

Now that's interesting because I have the matter of suitable lighting for
digital cameras in my mind, but thought it would be too OT for this group.
However, since you offered advice, can I just clarify that you mean 'strobe'
to be a flash-type light as opposed to the always-on flood-type which I
currently use? If so, why should I change my current lighting setup? (I am
thinking cost consequences here)

You don't need to at all. For flat work continuous ligthing or flash
can be used equally well.

Further, I seem to recall a white paper written by Betterlight on this
subject, and their eventual recommendations were to use fluorescent lighting
with a couple of filters (daylight AND tungsten, IIRC) to counter the
metamerism effect on certain colours when using digital sensors. Any
comments?

I'm not sure why they would say that. Flourescent is non-continuous in
spectrum and will not return the colors of artwork faithfully. ( I'm no
expert in this, but that's the way it would seem to me). Tungsten is
continuous but weaker at the shorter wavelengths, stronger at the longer
wavelengths.

For flat work I would guess that tungesten alone with the digital camera
body set to 2800K would be very good. (I've been shooting a lot of
tungsten photos and the whites look white.

Two flashes, and the camera set to 5500K is probably better than
tungsten for flat work, and softboxing them gives very even illumination
at the subject. Harder to use polarizers, but with digital you can
simply chimp and histo your way to the right exposure. Capture RAW to
really have a working file for post-proc.

Cheers,
Alan




--
-- r.p.e.35mm user resource: http://www.aliasimages.com/rpe35mmur.htm
-- r.p.d.slr-systems: http://www.aliasimages.com/rpdslrsysur.htm
-- [SI] gallery & rulz: http://www.pbase.com/shootin
-- e-meil: there's no such thing as a FreeLunch.

Siggy wrote:

lid wrote:


Yes. You're only foing to get a 29 degree FOV with that 50mm lens.


Hmm. I don't suppose you could also let me have the FOV (in degrees) of the
lens in my existing setup, could you? :-)


OK, that's a minimum of about 200 DPI. 3300 x 2338 pixels. About 8
megapixels.


Ok. Minolta D7 seems a bit weak in that respect then. Are we looking at the
Canon 350D here, I wonder?

For A3 the Maxxum 7D will do fine. So will the the 350D and I doubt you
would see much difference in the output images between the two. The
crop factor of the 350D is 1.6 (v. 1.5 for the 7D) and that will make
your larger frame copy work more difficult.

I don't want to sound like a shrill defender of the 7D, but given your
requirements I believe the output will be equally good to the eye as the
350D and less difficult to work with.

I mentioned that as I have always found (in an image containing significant
dark or shadow areas) it difficult to get the scanner to extract as much
detail from the dark areas of the photographic print without blowing out the
delicate highlights. However, I forgot that I shall be bypassing that stage
with a digital camera, so I stand corrected. Thanks.

Most particular if you capture RAW.

Cheers,
Alan

--
-- r.p.e.35mm user resource: http://www.aliasimages.com/rpe35mmur.htm
-- r.p.d.slr-systems: http://www.aliasimages.com/rpdslrsysur.htm
-- [SI] gallery & rulz: http://www.pbase.com/shootin
-- e-meil: there's no such thing as a FreeLunch.

Alan Browne wrote:
Siggy wrote:

Further, I seem to recall a white paper written by Betterlight on
this subject, and their eventual recommendations were to use
fluorescent lighting with a couple of filters (daylight AND
tungsten, IIRC) to counter the metamerism effect on certain colours
when using digital sensors. Any comments?

I'm not sure why they would say that. Flourescent is non-continuous
in spectrum and will not return the colors of artwork faithfully. (
I'm no expert in this, but that's the way it would seem to me). Tungsten
is continuous but weaker at the shorter wavelengths,
stronger at the longer wavelengths.

Two words - 'Cobalt Blue'. :-) It seems that this (often used artists
pigment) is extremely susceptible to turning purple under tungsten light,
and conventional methods to correct this only leads to creation of other
colour changes in other pigments. I have now found the white paper by Robin
Myers and provide the link here, should this interest you.
Website link only:
http://www.rmimaging.com/information...ion_index.html
and for the pdf itself::
http://www.rmimaging.com/information...hotography.pdf


Two flashes, and the camera set to 5500K is probably better than
tungsten for flat work, and softboxing them gives very even
illumination at the subject. Harder to use polarizers, but with
digital you can simply chimp

'chimp'?

and histo your way to the right
exposure. Capture RAW to really have a working file for post-proc.

Thanks again.